This invention relates to wire twisting devices used to twist a folded strand of wire about an object.
Wire twisting devices are known which are used to twist a folded strand of wire about an object to be secured. Such devices have a wide range of applications in such diverse areas as orthodontistry, oral surgery, orthopedic surgery, veterinary surgery and the aircraft industry. In general, the requirement for wire twisting devices in each of these applications is essentially the same: A strand of wire is looped about the object(s) to be secured, the free ends are gripped, and the gripped ends are twisted about one another until the desired amount of twisting is completed. Early wire twister designs employ modified pliers having jaws to grip the wire ends and some means for rotating the pliers about the longitudinal axis. Typically, some type of spiral groove arrangement is employed to provide the rotational motion in known devices.
All known devices suffer from the limitation that two hands are required in order to successfully use the device. One hand is normally used to grip the device, and the other hand is required for a variety of purposes, such as installing the free ends of the wire into the gripping jaws guiding the wire while it is being twisted or operating various components of the device. This two handed limitation is highly undesirable in most applications. For example, in orthodontistry the orthodontist should ideally have one hand free to use a dental mirror to inspect the effect of the progressive tightening of the wire being twisted on the patient's teeth. In an aircraft industry application, the mechanic should have one hand free in order to stabilize the device being secured. Similar limitations occur in nearly all applications.
In addition to the above noted disadvantage, known wire twisting devices also suffer from the disadvantage that many devices do not adequately grip the wire over the wide range of tension experienced by the wire as it is progressively tightened. In some arrangements, the tension may be initially adequate, but progressive tightening of the wire by twisting causes the free ends of the wire to slip along the gripping surface of the jaws, which is undesirable in many applications.
A further disadvantage with some known wire twisting devices lies in their use of a relatively large gripping head, which obscures the object(s) being secured from the view of the operator, leading to difficulty in operation.
Efforts to devise a wire twisting apparatus devoid of the above known disadvantages have not been successful to date.